﻿#region Copyright (c) 2003 - 2008, Andreas Mueller
/////////////////////////////////////////////////////////////////////////////////////////
// 
// Copyright (c) 2003 - 2008, Andreas Mueller.
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// which accompanies this distribution, and is available at
// http://www.eclipse.org/legal/epl-v10.html
//
// Contributors:
//    Andreas Mueller - initial API and implementation
//
// 
// This software is derived from software bearing the following
// restrictions:
// 
// Copyright (c) 1994
// Hewlett-Packard Company
// 
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee,
// provided that the above copyright notice appear in all copies and
// that both that copyright notice and this permission notice appear
// in supporting documentation.  Hewlett-Packard Company makes no
// representations about the suitability of this software for any
// purpose.  It is provided "as is" without express or implied warranty.
// 
// 
// Copyright (c) 1996,1997
// Silicon Graphics Computer Systems, Inc.
// 
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee,
// provided that the above copyright notice appear in all copies and
// that both that copyright notice and this permission notice appear
// in supporting documentation.  Silicon Graphics makes no
// representations about the suitability of this software for any
// purpose.  It is provided "as is" without express or implied warranty.
// 
// 
// (C) Copyright Nicolai M. Josuttis 1999.
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
// 
/////////////////////////////////////////////////////////////////////////////////////////
#endregion


using System.Collections.Generic;
using NStl.Collections;
using NStl.Iterators;
using NStl.Iterators.Support;

namespace NStl
{
	public static partial class  NStlUtil
    {
        /// <summary>
        /// Get a Start Iterator for a IList collection.
        /// </summary>
        /// <param name="l"></param>
        /// <returns></returns>
        public static ListIterator<T>
            Begin<T>(IList<T> l)
        {
            return new ListIterator<T>(l, 0);
        }
        /// <summary>
        /// Get an End Iterator for a IList collection.
        /// </summary>
        /// <param name="l"></param>
        /// <returns></returns>
        public static ListIterator<T>
            End<T>(IList<T> l)
        {
            return new ListIterator<T>(l, l.Count);
        }
        /// <summary>
        /// Removes a sequence from an IList&lt;T&gt;
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="first"></param>
        /// <param name="last"></param>
        /// <returns></returns>
        /// <remarks>
        /// Note that this is impossible for System.Array, 
        /// as all Remove() implementations are throwing, because 
        /// the Arrays have fixed size.
        /// </remarks>
        public static ListIterator<T> Erase<T>(ListIterator<T> first, ListIterator<T> last)
        {
            IList<T> list = first.List;
            if (first.List is List<T>)
            {
                List<T> l = (List<T>)first.List;
                l.RemoveRange(first.Index, last.Index - first.Index);
                return (ListIterator<T>)first.Clone();
            }
            if (IsVector(first))
            {
                Vector<T> v = (Vector<T>)first.List;
                v.Erase((Vector<T>.Iterator)first, (Vector<T>.Iterator)last);
                return (ListIterator<T>)first.Clone();
            }
            if (IsArrayList(first))
            {
                System.Collections.ArrayList l = (System.Collections.ArrayList)((IList2IlistTAdapter<T>)first.List).List;
                l.RemoveRange(first.Index, last.Index - first.Index);
                return (ListIterator<T>)first.Clone();
            }

            int at = first.Index;
            ListIterator<T> ret = (ListIterator<T>)first.Clone();
            for (; first != last; first.PreIncrement())
            {
                list.RemoveAt(at);
            }
            return ret;
        }

	    private static bool IsArrayList<T>(ListIterator<T> first)
	    {
	        return first.List is IList2IlistTAdapter<T>
	               && ((IList2IlistTAdapter<T>)first.List).List is System.Collections.ArrayList;
	    }

	    private static bool IsVector<T>(ListIterator<T> first)
	    {
	        return first.List is Vector<T> && first is Vector<T>.Iterator;
	    }
    }
}
